Effects of mulberry leaf flavonoid and resveratrol on methane emission and nutrient digestion in sheep

As a new type of methane control agent, natural plant extract has been widely studied in recent years, but in vivo studies are few. This study was to investigate the effects of the dietary supplementation of 2 different polyphenols on the methane (CH(4)) emission and digestion metabolism in sheep. Ten healthy crossbred sheep (Dorper ♂ × small-tailed Han ♀; BW 60.0 ± 1.73 kg) were used in a change-over design. The sheep were fed the following 3 diets in the present study: the basal diet (CON) with no supplementation; the basal diet supplemented with 2 g mulberry leaf flavonoid (MLF) per day per sheep; the basal diet supplemented with 0.25 g resveratrol (RES) per day per sheep. Both MLF and RES reduced CH(4) emission scaled to metabolic weight per kilogram of DMI and CO(2) output scaled to metabolic weight, but the effect of RES was significant (P < 0.05). Both MLF and RES significantly improved apparent digestibility of DM, OM, NDF, ADF, and nitrogen, but the effect of RES was significant (P < 0.05). Both MLF and RES significantly improved ME (P < 0.05) and reduced energy losses in CH(4) emission (P > 0.05). In conclusion, MLF and RES can improve the digestibility of nutrients, the utilization of nutrients and energy, and reduce CH(4) emission, but they are not conducive to nitrogen retention.